1. Field of the Invention
The invention relates to a motor vehicle door lock or the like that is an electric lock which is actuated by sensors in the lock mechanism. The present invention is also applicable to motor vehicle hood locks, hatch locks, etc.
2. Description of Related Art
A known motor vehicle door lock of the type to which the present invention is directed is disclosed in published German Patent Application DE-A-196 31 869 and corresponding, commonly owned, co-pending U.S. patent application Ser. No. 09/147,649. This lock is an electromechanical motor vehicle door lock in which the actuation of the detent pawl is produced, especially from the outside door handle or the inside door handle, by a chain of action of mechanical forces, while unlocking and locking of the door lock normally take place by means of an electronic remote control and an electrical central locking system drive. In an emergency, the unlocking function can also be performed mechanically from a closing cylinder on the door, such as the driver""s door.
In the above explained known motor vehicle door lock, there is a crash switch by which, in an accident, the lock mechanism is immediately shifted into the xe2x80x9cunlockedxe2x80x9d operating position independently of the control electronics so that actuation of the inside door handle immediately causes the detent pawl to be lifted.
Moreover, it is known from the above mentioned patent application that electrical actuation of the detent pawl can be attained by providing an electrical opening aid. One such purely electrically activated motor vehicle door lock is generally called an xe2x80x9celectric lock.xe2x80x9d In the explained prior art, this xe2x80x9celectric lockxe2x80x9d has a lock mechanism for mechanical activation of the detent pawl in case of an emergency.
In a motor vehicle door lock with the xe2x80x9cpassive entryxe2x80x9d function, it is assumed that only the approach of an operator to the motor vehicle triggers a corresponding opening of the door or other functions.
The use of an xe2x80x9celectric lock,xe2x80x9d especially in conjunction with the xe2x80x9cpassive entryxe2x80x9d function, instead of a known mechanical motor vehicle door lock with an electrical central locking system has long resulted in the door handle fittings needing to be modified or replaced because, instead of or in addition to the chain of action of a force which runs into the lock mechanism, various microswitches for actuating the electrical opening aid must be attached and connected to the motor vehicle door lock, specifically the control electronic located there, by means of corresponding cables.
Therefore, there exists an unfulfilled need for a motor vehicle door lock which can work as a pure electric lock and which is also suited for performing a xe2x80x9cpassive entryxe2x80x9d function. There also exists an unfulfilled need for such a motor vehicle door lock which allows ensured operation even when the electric power supply fails for whatever reason, including an accident. Moreover, there exists an unfulfilled need for such a motor vehicle door lock that can be used as a replacement for conventional motor vehicle door locks.
The primary object of the present invention is to devise a motor vehicle door lock which can work as a pure electric lock and which is also suited for a xe2x80x9cpassive entryxe2x80x9d function. .
Another object of the present invention is to provide such a motor vehicle door lock which allows ensured operation even when the electric power supply fails.
Yet another object of the present invention is to provide such a motor vehicle door lock that can be used as a replacement for conventional motor vehicle door locks.
In accordance with preferred embodiments of the present invention, these objects are obtained by an improved motor vehicle door lock that is an electric lock which is actuated by sensors in the lock mechanism. Therefore, in normal use, the chains of action of force from the outside door handle, the inside door handle, and optionally, the closing cylinder in the lock mechanics are used only to actuate the corresponding switches or to influence the corresponding sensors. As a result of existence of the chain or chains of action of mechanical forces, the lock mechanism can be used in a split second to activate the detent pawl, etc. in an emergency. In the implementation of an overrun function in which, for example, the outside door handle must be activated only up to a pressure point to trigger the electric function, no-load operation can be assigned to the chain of action of the force in the lock mechanism, such that the actuation of the outside door handle in the normal state takes place without exerting force on the detent pawl. Only in the special state, where there is a corresponding further pulling of the outside door handle beyond the pressure point, does the mechanical activation of the detent pawl take place.
According to the preferred embodiments of the present invention, however, there is a coupling switch which, in the special state, couples the chain of action of force, the chain of action of force being decoupled from the lock mechanism in the normal state. Thus, by moving the lock mechanism, mechanical actuation of the detent pawl can take place.
In addition to the above explained advantages, the motor vehicle door lock in accordance with the present invention has a major advantage in that it can be easily used as a replacement for conventional motor vehicle door locks. In particular, the outside door handles and the inside door handles of typical motor vehicle door locks can continue to be used simply with a central locking system and can also continue to work as before in the same way. The motor vehicle door lock in the present invention assigns to the outside door handles and inside door handles apparent mechanical functions in the normal state. In fact, only the electrical sensors in the lock mechanism are influenced. Only in the special state do the outside door handles and inside door handles and optionally a closing cylinder, act purely mechanically in the typical manner.
The reaction times are shortened so dramatically by the state changes in the motor vehicle door lock in accordance with the present invention which operates by purely electrical processes in the normal state, that extraordinarily low response times down to 100 ms are achieved.